This manual has been designed to support users with methodological guidelines for the analysis of facial images by establishing anatomical landmarks.

The cephalometric landmarks, for the most part, are related to fixed bony landmarks (craniometric landmarks), covered by a layer of muscular and adipose tissues. The successful use of craniometric points (Martin y Saller, 1957) caused an extrapolation to the soft tissue context, as intuitive analogues for craniofacial analysis where they are used to guide the superimposition process and for photo anthropometric analysis, where their usefulness lies in estimating distances between anatomical points and facial proportions. When locating the cephalometric landmarks, it should be tried that the bony landmark is at the same level, or at the corresponding place in the epidermis (since the relationship is not always perpendicular). For this reason, landmarks in the live, more specifically in facial images, are more difficult to determine and less precise than their homologues in the skull. For this reason, we see it necessary to illustrate the correct positioning of the cephalometric landmarks since it is essential for the analysis of faces from photographs, both from the morphological and metric point of view; being a complex task that depends on the variability in the positioning of the facial landmarks.

This manual has been designed for marking cephalometric (2D) landmarks with the tools provided by Skeleton·ID. The description and procedure for marking 21 facial landmarks in photographs, 11 medial and 10 bilateral, is included. For each landmark, the following is provided: standardized definition (Caple y Stephan, 2015); the Bookstein’s landmark type (Bookstein, 1991); the specific procedure for marking using Skeleton-ID, which includes vertical and horizontal reference lines to facilitate the visualization of the landmarks (at the intersection of both lines); and the visual references in frontal, lateral and oblique views to illustrate its location in the facial topography.